The DeKalb County Sheriff's Office ruled the death accidental, suggesting she fell from the cliff. The medical examiner who performed the autopsy mentioned blunt trauma consistent with a fall and possible drowning and pointed out Agee was intoxicated.

Their doubt began the moment they found her body, when they say Chris Stout and Aaron Lilly immediately appeared.

“On the way out there, I saw the two boys in a canoe hanging on to a house boat just waiting, directly looking at where the body was,” Chris Yarchuck said. "When we come back, they started screaming 'our friend is missing our friends missing.' It seemed staged."

When the deputies started asking questions, things got even stranger.

“Spending time with Chris and Aaron I could definitely tell something was wrong there,” Ryan Melenson said. "The way they lawyered up. The way Aaron said 'let me do the talking.' Their demeanor; no remorse. They weren't saddened by the loss of their friend. They were scared. They had the wrong body language."

New witnesses come forward

Now two new witnesses have come forward including Aaron Lilly's ex-girlfriend, who says the DeKalb County investigator was not interested in what she had to say about Aaron's past.

“I told him start to finish what I knew, and I even told him Aaron did have a violent past and that's why we broke up," Kassie Franks said. "He said that has nothing to do with it, there is no violence in this matter, it was an accident and we are trying to prove it was an accident."

Franks was interviewed by law enforcement because earlier that evening she had an altercation with Hannah Palmer over their dating history with Aaron Lilly.

The fight in the parking lot made the police report but nothing about Aaron's past.

Kassie Franks said she even showed the detective pictures of her injuries; bite marks, bruises, even one on her neck, and talked about the night he was arrested.

“He lunged at me, was wording; 'I hate you' just kinda like calling me things," Franks said. "Then he got into his cell and was hitting the glass, flicking me off telling me he hated me," Franks said.

None of that, by the way, is in the DeKalb County investigative report. Franks said the whole interview ended with a warning.

“He [the investigator] even said before I walked away 'other people are going to be reaching out to you, the family is crazy, they are getting PI's and you're safe if you talk to me, but if you talk to anybody else I can't protect you'," Franks said. "He tried to scare me."

The family always felt the investigation was rushed and sloppy.

The 911 calls made that day are missing. When Agee's mom Sherry Smith asked for Lauren’s belongings, she said the DeKalb County Sheriff’s Office said it didn’t have them.

“Sleeping bags, clothes, flip-flops, most of what she brought; they had no idea,” Smith said.

The family hired a private investigator, who went to great lengths to demonstrate that although the cliff is steep it is impossible to get to the water. It is on a slope with trees, bushes, rocks, even pathways. If she did fall in, where is the evidence?

“Police have said she fell off the cliff, but exactly where did they she fell," Private Investigator Sheila Wysocki said. "Show me the pictures of the blood on the rocks. Show me the broken twigs."

Wysocki said they had seven people look over the case, veteran investigators, and all seven have the same questions.

Since our earlier stories aired, a witness named Chris Brown came forward.

Brown is a father and small business owner who was staying Center Hill Lake over the weekend with his family.

“Right at midnight I was shocked to see a white male swimming toward the dock," Brown said. "I saw this young man climb up on the dock. The young man appeared extremely distraught and worn out. He was spitting up water for several minutes. The young man told us that he had almost drowned when he swam from the area of the bluff to the marina dock."

Brown believes he saw Lilly the night of Agee's death.

"I am sure that Lilly is the young man that came up out of the water that night," Brown said.

He also reported what he saw to law enforcement.

"I called the DeKalb County Sheriff's Office to report what i had seen," Brown said. "The DeKalb County Sheriff's Office advised me that if it became of interest, they would contact me back. I never was contacted again by their office."

This statement directly contradicts what Aaron Lilly told police about that night; that they were all in bed at the campsite by midnight.

Despite all this, the case is closed.

Read Brown's full witness account to law enforcement below or here on mobile.

What happens next

The only person who can open it up is the District Attorney Bryant Dunaway. He has the authority to bring in a new independent investigation.

He has not done that. Why- we don't know. He has not returned our calls since February.

“This family has done nothing wrong," Wysocki said. "They just want answers. Instead they have to pay and pay and pay to get an investigation done."

Aaron Lilly is now living in south Florida. He is engaged to be married to Hannah Palmer.

Christopher Stout pleaded guilty to his third DUI and is spending a year in jail in Rutherford County.